while kate middleton, duchess of cambridge, spent a day in a hospital in london. the early baby buzz is turning into the early baby. brandi hitt has the royals celebrating and, of course, speculating. >> reporter: the royal wait is over. prince william and wife kate are expecting their first child and drawing congratulations from around the world. >> it's absolutely wonderful news, and i'm delighted for them. i'm sure they will make absolutely brilliant parents. >> reporter: the future queen of england was in her first trimester after kate was hospitalized with hyperemesi hyperemesis gravidarum, a rare condition that causes severe vomiting and dehydration, and h.g. can give a hint about the baby. >> hyperemesis gravidarum is more common in people carrying twins. >> reporter: 18 months after their fairy-tale wedding, the world has been on baby bump watch, and the royal couple has kept everyone guessing. william even told katie couric last may they wanted to start a family. >> i'm just very keen on having a family, and both catherine and i are looking forward to hav